It is common practice in the manufacture of electric motors to individually test newly manufactured motors under load to verify proper motor performance and to identify any of a number of potential defects which may have occurred in the manufacturing process. In conventional practice, the armature of a motor under test is connected to a dynamometer, and the motor windings are energized at a typical operating point. The motor voltage, current, power factor, and the like are typically measured and compared to limit values to generate a pass/fail indication for the motor.
With the above-described test procedure, the dynamometers must be carefully calibrated and aligned in order to prevent unwarranted motor fail indications. This, of course, can be very costly and time consuming.